“I can't hear my surround speakers” is a very common consumer complaint.
As the volume level of a multi-channel audio system is varied from the presentation sound level at which the program material was mixed in a calibrated mixing studio, the listener is no longer presented with the same surround experience as at the presentation sound level. Except for occasional special effect sounds, the ambient material in the surround channels is recorded at a very low level relative to the front channels, so as system volume is reduced the ambient surround content is masked by environment noise or falls below the threshold of hearing. The problem is compounded when the system has no way of matching the studio performance sound level.
To allow a more acceptable low level listening experience a variety of manufactures offer a “late night listening” feature which upon user activation applies various types of level adjustments to a sound system. The changes applied by these systems are not based on the actual recorded levels or the particular playback conditions in the home rather they are arbitrary and subjective. Without knowing the performance sound levels from the studio or the sound level of the home they cannot match the experience of the original material as it was recorded at the performance sound level in the studio.